Modbus Register - Siemens SITRANS LG270 Operating Instructions Manual

General configuration of the host
The data exchange with status and variables between field device and host is carried out via
register. For this, a configuration in the host is required. Floating point numbers with short prevision
(4 bytes) according to IEEE 754 are transmitted with individually selectable order of the data bytes
(byte transmission order). This "Byte transmission order" is determined in the parameter "Format
Code". Hence the RTU knows the registers of the SITRANS LG270 which must be contacted for the
variables and status information.
Format Code
0
1
2
3

10.3 Modbus register

Holding Register
The Holding registers consist of 16 bit. They can be read and written. Before each command, the
address (1 byte), after each command, a CRC (2 byte) is sent.
Register Name Register Num-
ber
Address 200
Baud Rate 201
Parity 202
Stopbits 203
Delay Time 206
Byte Oder (Float- 3000
ing point format)
Input register
The input registers consist of 16 bits. They can only be read out. Before each command, the ad-
dress (1 byte) is sent, after each command a CRC (2 bytes) is sent.
PV, SV, TV and QV can be adjusted via the sensor DTM.
Register Name Register Number
Status 100
PV Unit 104
PV 106
86
Byte transmission order
ABCD
CDAB
DCBA
BADC
Type Configurable
Values
Word 1 ... 255
Word 1200, 2400,
4800, 9600,
19200
Word 0 = None, 1 =
Odd, 2 = Even
Word 1 = None, 2 =
Two
Word 10 ... 250
Word 0, 1, 2, 3
Type Note
DWord Bit 0: Invalid Measurement Value PV
Bit 1: Invalid Measurement Value SV
Bit 2: Invalid Measurement Value TV
Bit 3: Invalid Measurement Value QV
DWord Unit Code
Primary Variable in Byte Order CDAB
SITRANS LG270 - Operating Instructions
Default Value Unit
246 -
9600 -
0 -
1 -
50 ms
0 -
PBD-51041066